The RADiation Impacts on Climate and Atmospheric Loss Satellite (RADICALS) is a low-Earth orbiting Canadian small satellite mission investigating the transport of space radiation into the atmosphere, and its impact on Earth’s climate. Scheduled for launch in late 2026, the mission will launch into a polar orbit with an integrated payload comprising two back-to-back look direction High Energy Particle (HEP) telescopes, an X-Ray Imager (XRI) to remote sense energetic particle precipitation using back-scattered Bremsstrahlung X-rays, and a boom mounted FluxGate Magnetometer (FGM) and Search Coil Magnetometer (SCM). Using an innovative Thomson spin-stabilized configuration, the satellite will sample the pitch angle distributions in the spin-plane twice per spin. The back-to-back HEP look directions allow for a contemporaneous view of the down-going and back-scattered up-going electrons, at the same time as XRI remote-senses the related Bremsstrahlung, and the magnetometers provide in-situ magnetic signatures of a range of plasma waves. The key measurement of the pitch angle resolved energetic electron precipitation (EEP) and related back-scatter, including a resolved loss cone, will allow a detailed assessment of the energetic particle energy input to the atmosphere. Measurements of EEP, in addition to measurements of solar energetic particle (SEP) precipitation, will represent a critical data set for assessing the role of space radiation in the climate system, for example through the catalytic destruction of ozone in the middle atmosphere by NOx and HOx. Accurately quantifying the impacts of this space radiation on climate requires accurate and loss cone-resolved characterization of the flux of these precipitating energetic particles for inclusion into whole atmosphere models. The RADICALS explorer will also enable research into potentially catastrophic space-weather radiation effects on satellite infrastructure, and assess impacts on space weather-related interruptions to high frequency radio communications including in relation to aircraft operations in polar regions. Additional cube- and micro-satellite missions, together with the RADICALS, could form a powerful mini--constellation exploring the space weather-climate system.

Over the past couple of decades, small satellites have evolved from demonstrators to operational assets to enable low-cost space access for government services and commercial service providers. The Norwegian AIS constellation is an example of how small satellites have revolutionized global ship traffic monitoring, and how a satellite program grows from a single payload on nanosatellites to multiple payloads exploring new science as well as new maritime services on microsatellites. This chapter discusses the Norwegian satellite missions, with an emphasis on the unique and innovative aspects that made spaced-based AIS extremely valuable and of long-term strategic importance to Norway.

Modern small satellite constellations are demanding quick spacecraft commissioning and high duty cycle for their payload operations. In a conventional small satellite mission architecture, operations time is often split between different modes that require different spacecraft attitudes to achieve their goal. For example, drag-based orbit maneuvering can be used for creating relative separation between constellation members, and with spacecraft consisting of single rigid bodies, dedicated attitude manipulation is required to perform these operations. The attitudes that take advantage of the body asymmetries to modify the drag area are generally incompatible with the attitude maneuvering required for payload operations. At the constellation scale, these downtimes in the payload operation schedule can greatly reduce the overall capability of the system. By including deployable, articulating solar arrays in the design of small spacecraft, array pointing can be decoupled from the main payload pointing operations. With these pieces decoupled, payload operations can proceed uninterrupted while the articulating arrays enable power generation or drag-based orbit maneuvering. The focus of this paper is the demonstration of the articulating arrays as a means of enabling drag-based orbit phasing, while agile attitude maneuvering for payload operations proceeds concurrently. The dynamic equations of the multibody system are derived, and guidance, navigation, and control considerations for achieving decoupled attitude and articulation objectives are presented. Results are shown for attitude performance as well as for the orbit maneuvering performance achieved through array articulation.

As the effects of greenhouse gas (GHG) and issues resulting from air quality (AQG) become more prevalent, there is increasing motivation for industrial operators to quantify and ultimately reduce their emission footprint. GHGSat Inc., utilizing novel satellite technology developed in partnership with the Space Flight Laboratory, intends to become the global leader of remote sensing of GHG, AQG, and other trace gas emissions. Phase one: GHGSat-D (Claire) launched in June 2016, becoming the first microsatellite with a high-resolution instrument designed to measure greenhouse gas emissions from point sources. With over 3000 site measurements made worldwide, GHGSat-D has proven how effective satellite technology is paving the way forward for a worldwide monitoring initiative: GHGSat Constellation. Phase two: GHGSat-C1 and GHGSat-C2 are in development as first in a fully operational constellation allowing continued enhancement of the satellite design. These enhancements include hardware redundancy and improved electromagnetic compatibility to increase performance and reliability, upgrades to the primary optical payload to reduce the effects of stray light, allow for onboard calibration and improved radiation mitigation, and an optical downlink to increase the downlink capacity of the platform. GHGSat-C1 is scheduled for launch in Q3 2019 with GHGSat-C2 following in 2020.

Satellite AIS is well recognized as a system for vessel traffic monitoring and maritime safety. The growing demand for maritime data services has led to the development of a new VHF Data Exchange System (VDES), which will provide two-way communication at higher data rates than possible with current AIS systems. Within the VHF maritime frequency band (156.025-162.025 MHz), VDES integrates AIS with channels for Application Specific Messages (ASM) to support the distribution of maritime data, including meteorological data and traffic information. Expanding VDES to a satellite platform will facilitate a global data exchange between ships and shore via satellite. NorSat-2 is the first satellite to incorporate a VDES payload, in addition to an advanced AIS receiver, both of which are in-orbit reconfigurable software-defined radios developed by Kongsberg Seatex. NorSat-2 was developed and built by the Space Flight Laboratory (SFL) under contract to the Norwegian Space Centre, with contribution from Space Norway for accommodation of the VDES payload. With a mass of 16 kg, the satellite design is based on SFL's Next-generation Earth Monitoring and Observation (NEMO) bus, which has proven flight heritage to be a robust and reliable microsatellite platform. To enable directional communication over VHF for the VDES payload, SFL has developed a three-element deployable Yagi-Uda antenna. The antenna is stowed during launch and deployed on-orbit upon command receipt. In addition to NorSat-2's S-band telemetry and command system, the satellite also has an enhanced S-band feeder uplink which is capable of achieving data rates of up to 1 Mbps. NorSat-2 launched onboard a Soyuz on July 14, 2017 into a 600 km polar sun synchronous orbit. It is the fourth Norwegian satellite on-orbit and is one of the first satellites to supply VDES services, in addition to complementing Norway's existing satellite AIS network. This paper describes the NorSat-2 mission, with an emphasis on the unique and innovative aspects that are the VDES payload, deployable Yagi antenna, and enhanced S-band uplink.

The CanX-7 nanosatellite successfully tested a unique deorbiting technology by deploying four thinfilm polyimide drag sail segments in May 2017. Drag sails increase satellite cross-sectional area augmenting atmospheric drag, helping accelerate a satellite’s deorbit. This small size, weight and power deorbiting technology is well-suited to small satellites as they often cannot accommodate classical chemical thruster-based systems due to their compact design. During the deployment of the drag sails, ground based observers in eastern Ontario used electro-optical telescopes to monitor the photometric (brightness) changes of CanX-7. This paper examines the detected photometric characteristics of the CanX-7 nanosatellite as detected by small telescopes in Canada prior to, during and after the drag sail deployment. The ground-based observations validated satellite telemetry from SFL indicating that the first two drag sail segments deployed successfully. The second set of sails, deployed on the subsequent orbit, was not unambiguously detected from the ground-based sensors, however their deployment was verified in CanX-7’s telemetry. Weeks later, follow-up photometric measurements of CanX-7 shows an increase in its body rate between 0.6-1.7 rpm suggesting torques acted on CanX-7. This behavior was expected and will continue until the spacecraft aero-stabilizes due to increasing air density at lower orbital altitudes. INTRODUCTION Small satellites are showing great promise for widespread use in both private and government space systems. However, a recurring issue is that their compact form factor makes them inherently longlived in orbit increasing their chance of becoming long-lived space debris. Due to small satellite’s relatively high ballistic properties, this class of space vehicle can dwell in orbit for hundreds of years exceeding the guidelines of the Inter Agency Debris Coordination Committee (IADC) which recommends deorbiting a satellite within 25 years after the end of its mission life [1]. Given small satellites’ economic appeal due to their lower cost, and a favorable market environment savoring increased data production, the possibility of increased space debris generation in Low Earth Orbit (LEO) higher than 650 km becomes a distinct possibility. Recognizing this technology gap in deorbiting of small satellites, the University of Toronto Space Flight Laboratory (SFL), initiated the CanX-7 satellite technology demonstration. Upon the completion of its ADS-B (aircraft detection) demonstration mission [2], CanX-7 would deploy a 4 m 2 drag sail to test the suitability of sails to deorbit nano and small-satellite platforms. Drag sails are an elegant solution to deorbit small satellites as they are lightweight, do not require active attitude control or power from the satellite and do not store energetic propellants which could explode thereby adding to the space debris problem. The CanX-7 drag sail deployment represented a unique observational opportunity for the Space Situational Awareness (SSA) community to observe a nanosatellite rapidly change shape and size in orbit. As such, Defence R&D Canada approached SFL to coordinate an observing opportunity during the deployment of CanX-7’s drag sail segments. On 4 May 2017, the CanX-7 nanosatellite deployed its drag sail segments while simultaneously observed by ground based electro-optical telescopes at

In November 2014 the CanX-4 and CanX-5 spacecraft became the first nanosatellites to demonstrate autonomous formation control with error less than 1 m. This feat was accomplished both in along-track formations at 1000 and 500 m range and projected circular orbit formations at 100 and 50 m. This control performance was enabled through carrier-phase differential GPS navigation techniques, providing online relative state estimates typically accurate to better than 10 cm. It was an important milestone on the road to regular and fully operational formation-flying missions. This paper provides an overview of the relative positioning algorithm design, presents an independent assessment of the receiver performance, and assesses the absolute and relative navigation results. The mission's on-orbit results are compared with an independently determined orbit solution computed using the GPS High Precision Orbit Determination Software Tools at the German Aerospace Centre.

There is a growing demand for small yet effective satellite technologies. One area which needs to be addressed is compact propulsion systems capable of performing on-orbit maneuvers, station-keeping, and de-orbit impulses. An important consideration for propulsion systems is the safety and ease of handling, integrating, and testing. Maintaining simplicity by avoiding toxic propellants such as hydrazine is of particularly importance for small satellite developers. This paper summarizes a Space Flight Laboratory research project aimed to improve the efficiency of an existing system: SFL’s nitrous oxide resistojet. The resistojet is capable of providing 100 mN of thrust at a specific impulse of 105 s and input power of 75 W. The resistojet design was modified to achieve catalytic decomposition of the propellant. The monopropellant thruster prototype has successfully demonstrated sustainable nitrous oxide decomposition providing a thrust of 100 mN at a specific impulse of 131 s (25 % increase) and operational endurance of greater than 50 hours all while consuming minimal power. Ongoing research focuses on evaluating different catalysts in an effort to extend the operational lifetime of the system.

Chapter 41 Next-generation for Earth Monitoring and Observation – High Definition Imaging and Video of Earth Jakob Lifshits, Jakob LifshitsSearch for more papers by this authorLuke Stras, Luke StrasSearch for more papers by this authorSimon C. O. Grocott, Simon C. O. GrocottSearch for more papers by this authorFreddy M. Pranajaya, Freddy M. PranajayaSearch for more papers by this authorRobert E. Zee, Robert E. ZeeSearch for more papers by this author Jakob Lifshits, Jakob LifshitsSearch for more papers by this authorLuke Stras, Luke StrasSearch for more papers by this authorSimon C. O. Grocott, Simon C. O. GrocottSearch for more papers by this authorFreddy M. Pranajaya, Freddy M. PranajayaSearch for more papers by this authorRobert E. Zee, Robert E. ZeeSearch for more papers by this author Book Editor(s):Shen-En Qian, Shen-En Qian Canadian Space Agency, CanadaSearch for more papers by this author First published: 20 November 2015 https://doi.org/10.1002/9781118945179.ch41 AboutPDFPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShareShare a linkShare onFacebookTwitterLinked InRedditWechat Summary NEMO-HD (Nanosatellite for Earth Observation and Monitoring - High Definition) is a small spacecraft designed and built by the Space Flight Laboratory (SFL) for the Slovenian Centre of Excellence for Space Sciences and Technologies (SPACE-SI). This spacecraft performs a multitude of roles, from acting as an experimental test bed for the development of novel control and image processing algorithms, to providing a commercial service offering rapid response for monitoring crops and the effects of environmental disasters. Data from NEMO-HD is also used to augment terrestrial mapping services. Weighing in at 65 kg, this light-weight spacecraft builds on the experience acquired during the design and construction of SFL's other optical remote sensing missions to deliver a new level of performance in a very small package. NEMO-HD is designed to provide moderate-to high-resolution Earth imagery in a number of bands, including pan, blue, green, red and near infrared channels. In addition, NEMO-HD carries two high-definition video channels, each providing real-time video at 25 frames per second. The video channels are co-boresighted with the still imagery channels. This allows for a unique real-time imaging mode, in which an operator views the real-time video feed and commands the spacecraft to image a target of interest. Optical Payloads for Space Missions RelatedInformation

The Nanosatellite for Earth Monitoring and Observation Aerosol Monitor (NEMO-AM) is a high performance spacecraft in the final stages of development at the Space Flight Laboratory (SFL). The mission is funded by the Indian Space Research Organization (ISRO) with the purpose of detecting atmospheric aerosols in multiple bands over particular geographical areas with sub-degree accuracy. The satellite design leverages the lessons learned on previous SFL missions and, in part, is developed around the Generic Nanosatellite Bus concept, where a multipurpose and adaptable satellite bus is designed to work with a wide range of payloads with little or no modification. Consequently, many of the hardware components on NEMO-AM are inherited from the Generic Nanosatellite Bus and likewise boast flight heritage. The satellite also employs new technologies facilitated by commercial off-the-shelf hardware. This enabled shorter design cycles, but allowed those periods to be focused more on mission specific goals. The satellite bus envelopes a volume of 20 cm x 20 cm x 40 cm (main body) and has a mass of 16.1 kg with a power throughput capability of 80W. NEMO-AM will fly a standard suite of Attitude and Orbit Control Subsystem components found on the Generic Nanosatellite Bus, a GPS receiver, communication antennas (S-band for uplink and downlink), onboard computers for task management, a power distribution network including batteries and solar cells, and a multi-spectral imager to capture aerosol concentration measurements.

On 28 September 2015, exactView-9 (EV9) was launched into a 650 km equatorial orbit by an Indian Polar Satellite Launch Vehicle (PSLV) from the Satish Dhawan Space Centre. Housing an advanced Automatic Identification System (AIS) receiver from Kongsberg Seatex, the primary mission of EV9 is to provide ship detection services in the shipping corridors around the equatorial regions of Earth for exactEarth Ltd., a leading provider of satellite AIS data services. EV9 is a 5.5 kg satellite based on the Generic Nanosatellite Bus (GNB) satellite platform, and was designed, assembled, and commissioned by the Space Flight Laboratory (SFL). The satellite has a three-axis attitude determination and control system (ADCS) capable of terrestrial target tracking, making EV9 one of the smallest satellites to demonstrate this high performance capability on orbit. Coupling the attitude control system with a high data rate S-band transmitter, supporting rates up to 2048 kbps, EV9 is able to downlink over 1 GB of data per day to its ground station in Panama. Acting as a bent pipe relay, the satellite is capable of streaming AIS messages in real-time or downlinking data collected from around the globe during one pass each orbit.

In November 2014, only five months following launch, the CanX–4 and CanX–5 dual-spacecraft formation-flying mission became the first nanosatellites to successfully demonstrate autonomous formation flight with sub-metre control error and centimetre-level relative position knowledge. This achievement was preceded by a rapid commissioning phase and orbit acquisition manoeuvres, which brought the two satellites from a maximum range of 2300 km to a closest controlled range of 50 m during formation flight. Launched on 30 June 2014 from Sriharikota, India on board the Polar Satellite Launch Vehicle (PSLV), CanX–4 and CanX–5 were deployed separately, after which a series of drift recovery manoeuvres were executed to bring the spacecraft within communications range of each other. Subsequently, the spacecraft used cold gas propulsion, an S-band intersatellite communications link, and relative navigation using carrier-phase differential GPS techniques to perform a series of precise, controlled, autonomous formations with separations from 1 km down to 50 m. The achievements of CanX–4 and CanX–5 have set the benchmark for small satellite formation flight, and the technologies and algorithms developed for this mission enable a number of future applications, from on-orbit inspection and repair to sparse aperture sensing, interferometry, and ground-moving target indication.

BRITE (BRIght Target Explorer) Constellation, the first nanosatellite mission applied to astrophysical research, is a collaboration among Austria, Canada and Poland. The fleet of satellites (6 launched, 5 functioning) performs precise optical photometry of the brightest stars in the night sky. A pioneering mission like BRITE - with optics and instruments restricted to small volume, mass and power in several nanosatellites, whose measurements must be coordinated in orbit - poses many unique challenges. We discuss the technical issues, including problems encountered during on-orbit commissioning (especially higher-than expected sensitivity of the CCDs to particle radiation). We describe in detail how the BRITE team has mitigated these problems, and provide a complete overview of mission operations. This paper serves as a template for how to effectively plan, build and operate future low-cost niche-driven space astronomy missions.

In November 2014, only four months following launch, the CanX–4 and CanX–5 dual-spacecraft formation-flying mission achieved what has never been accomplished before, and successfully completed all of its mission goals with unprecedented precision and speed. This achievement—a series of autonomous formations with sub-metre control and centimetre-level relative position knowledge at the nanosatellite scale—was preceded by a rapid commissioning phase and orbit acquisition manoeuvres, which brought the two satellites from a maximum range of 2300 km to a closest controlled range of 50 m during formation flight. Launched on 30 June 2014 from Sriharikota, India on board the Polar Satellite Launch Vehicle (PSLV), CanX–4 and CanX–5 were deployed separately following launch, after which a series of drift recovery manoeuvres were executed to bring the spacecraft within communications range of each other. Subsequently, the spacecraft used onboard propulsion, an S-band intersatellite communications link, and relative navigation using carrier-phase differential GPS techniques to perform a series of precise, controlled, autonomous formations from 1 km range down to 50 m separation. The achievements of CanX–4 and CanX–5 have set the high mark for small satellite formation flight, and the technologies and algorithms developed for this mission enable a number of future applications, from on-orbit inspection and repair to sparse aperture sensing, interferometry, and ground-moving target indication. This paper describes the CanX–4 and CanX–5 mission and its exciting results, with an emphasis on launch, commissioning, relative orbit acquisition and phasing, and autonomous formation flight.